Paywall, https://iubmb.onlinelibrary.wiley.com/doi/abs/10.1002/biof.1566 Scihub, not available at time of posting.
For many years I've used a combo milk thistle/dandelion powder/ turmeric supplement, which helps with headaches, and brain fog. I checked on the turmeric with the supplement company and it's from Japan, if I recall correctly. The company tests for heavy metals etc. The turmeric is not contaminated with lead or other heavy metals, and toxic chemicals.
Yes, a shocking read. I forwarded this article to the supplement company whose products I buy, and they replied about where their supply of tumeric comes from, and the testing they do re contamination. Their response was as reassuring as these things can be given we have toxins everywhere.
The idea that turmeric is the reason for India's lower rate of dementia & Alzheimer's (AD) is too simplistic. While it may turn out to be a contributing factor there are bound to be a multitude of reasons. For example.... "The frequency of the APOE4 allele, a well recognized risk factor for AD is reported to be low in the Indian population in general, with regional differences. The frequency of the APOE4 allele is lower in the north, and central Indian populations compared with the US population." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3553547/
Agree about India. In the U.K. it is only quite recently - 20 years- since some (not particularly effective) medication became available that dementia diagnosis and cause of death has been taken up and recorded. It is spoken about much more openly and deaths are no longer put down to pneumonia etc. Dementia is the highest cause of death in women in the U.K. nowadays It could simply be that in India dementia is under diagnosed and not reported as cause of death rather than the prevalence being lower.
(Sorry, just entertaining myself here) Yes, the average life expectancy in India is about 68 years, it's around 80 years in Western countries. https://www.ncbi.nlm.nih.gov/pubmed/16173292 There's some 2014 UK data suggesting the prevalence of dementia in 70 to 74 year olds is around 3%; the prevalence of 80 to 84 year olds is around 12% and 90 to 94 year olds is 30%. In a good study in Maharashtra in India (looks to be lots of turmeric eaten there) with actual screening of people randomly selected from census data, the prevalence in 71 to 75 year olds was 2.2%, the prevalence in 81 to 85 year olds was 10% and in people aged 86 and above it was 18%. I think your chance of staying alive and adding to the dementia statistics if you are a person with dementia in a western country is a lot higher than if you live in a poor family in India. Given that, I'm not seeing much epidemiological evidence for turmeric helping.
A while ago I did some researching into the science around turmeric/curcumin and the studies I found showed that the doses that appeared to show any therapeutic benefits (unrelated to dementia) were very large doses that are way beyond what a person could realistically ingest. Also turmeric/curcumin can interact with medications.
Here's my experience with fresh turmeric root. I make golden milk with freshly grated turmeric root and have found that it helps relieve achiness in my fingers.